AbstractA giant e^± pair halo is formed by electromagnetic cascades developing around an AGN under the intergalactic magnetic field (1nG - 1μG). Many studies have been focussed on the pair halos in the gamma band because it has been predicted that the e^±s in the pair halos up-scatter the Cosmic Microwave Background (CMB) to be gamma-rays. However, the pair halos do not emit only gamma photons but also X-ray photons via synchrotron radiation. In this paper, the Spectral Energy Distributions (SEDs) and the angular distributions of the synchrotron radiation of the pair halos from the Monte Carlo simulations will be discussed.